Standard Operating Procedure (SOP) for Quartz dissolution in Hydrofluoric Acid

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Wilfred Owen
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1 Standard Operating Procedure (SOP) for Quartz dissolution in Hydrofluoric Acid #1 General Process Description This SOP describes the initial Quartz-sample dissolution (digestion). The sample is dissolved in Hydrofluoric Acid and is then ready for further chemical processing. There is no Hydrofluoric waste generated, as the small amounts of HF are evaporated. All work described in this SOP will have to be conducted in Mitchell A20. Contact Principal Investigator (PI): Prof. George E. Hilley for more information or (650) ). This SOP is from 05/04/2007. #2 Hazardous Chemicals/Class of Hazardous Chemicals We are using diluted Hydrofluoric Acid and Nitric Acid in this SOP. All equipment that came into contact with the acid mixture must be wiped and rinsed off. All wipes are hazardous waste and belong into the hazardous waste container near the 55gl drum. #3 Personal Protective Equipment (PPE) Before any acid is handled, ensure that you will at least meet the following protective requirements: 1. goggles (prescription glasses are not enough!) 2. double glove - neoprene 3. closed-toe shoes with socks 4. long pants (no shorts!) 5. lab coat 6. face shield 7. neoprene apron 8. small Chemical Spill Kit All Material Safety Data Sheets (MSDS) are located in the red folder in the storage cabinet opposite of the dishwasher under the vertical laminar flow unit.

2 Ensure the Calcium Gluconate is not expired and is available in the event of an exposure. The Calcium Gluconate is stored below the sink right next to the entrance door and in the closet above the sink right next to the entrance door. #4 Engineering / Ventilation Controls All work is done in the fume hood. Do not use any concentrated Hydrofluoric or Nitric Acid outside the fume hood. #5 Special Handling Procedures and Storage Requirements Be extra careful and alert, when handling the concentrated Hydrofluoric Acid container. The Hydrofluoric Acid is stored beneath the fume hood remove from the acid storage cabinet and place into the fume hood. The fume hood is the designated space for all work with Hydrofluoric Acid in this SOP. Only work with one sample at a time. Do not place more than 4 400mL Teflon beakers on a hot plate. Close the concentrated Hydrofluoric Acid bottle after use. While samples are digesting, no other work is allowed in the fume hood! Once all Hydrofluoric Acid has been poured, place the concentrated HF container back to the acid cabinet. Wash the measuring cylinder that you used for pouring concentrated HF with tap water. The first rinse goes into a waste container with a proper Stanford Hazardous Waste label (preferable the 55 gal drum near the door). Rinse measuring cylinder three times with milliq water. These rinseates can go down the drain. No rinseates with ph below 5.5 may be drain disposed. Please review the last page for emergency contact and notifications. #6 Spill and Accident Procedures If you spill acid and the spill is an immediate threat to your health, call Remain nearby. In the event of an HF exposure, follow Stanford University Hydrofluoric Acid First Aid Instructions posted in Mitchell A20. 2

3 If you accidentally spilled the diluted Hydrofluoric Acid (e.g., while placing the beakers on the hot plate): Don t panic! Remain calm. If the spill is small (less than a few ml up to 30mL), place a pads from small spill kit over the spill. Find a plastic/neoprene-disposal bag in the shelf above the scales and carefully place the soaked pads into the bag, and place in container provided with kit. To minimize contact with HF during clean-up, use Teflon tongs to move the soaked pads into the bag. Always wear two pairs of neoprene gloves when handing any spill with HF. If the spill is significant larger (> 0.5L) use the yellow spillcontainment pads under the sink by the door. Place them over the spill. Call If spill is greater than 30 ml, or cleanup takes longer than 15 minutes, document the cleanup activity either by calling EH&S at or by notating the lab inspection forms. If you have spilled small amounts of concentrated Hydrofluoric acid while pouring, carefully place a small spill kit pad over it and wipe it off. Alternatively, you can use the yellow spillcontainment pads. Rinse the area with plenty of water, collect rinseate into the 55gl drum, and wipe off afterwards. To confirm that cleanup is complete, wipe area with moistened ph paper. #7 Waste Disposal If you ve spilled acid and soaked up acid containment bags, make sure they are in disposable neoprene bags placed into the container provided by EH&S These containers will be labeled with an Stanford Hazardous Waste EH&S label and disposed separately. #8 Training requirements Prior to entering and working in the laboratory, you must have completed the EHS-4200 General Safety Training and EHS-1900 Chemical Lab Safety. You will have to retain training documentation for at least one year. Any person conducting work in Mitchell A20 using this SOP must receive training on the contents of this SOP. 3

4 #9 Approval Required All research staff must get initial PI approval prior to starting work with Hydrofluoric Acid. Under no circumstances it is allowed to work with concentrated HF, while being alone in the laboratory. Always ask a second person to be in the lab with you. If you have to work with concentrated HF and you are alone, you have to ask for approval from the PI, Prof. George E. Hilley. #10 Decontamination All glassware and measuring cylinders that have been used during the process should be thoroughly rinsed with Tap water (1 time), DI water (2 times) and then with Millipore water (2 times). Collect first rinseate as hazardous waste into the 55gl drum. #11 Designated Area All work must be done in the designated area in the fume hoods. Upon leaving a designated work area, remove any personal protective equipment worn and wash hands, forearms, face, and neck. After each use (or day), wipe down the immediate work area and equipment to prevent accumulation of chemical residue. At the end of each project, thoroughly decontaminate the designated area before resuming normal laboratory work in the area. 4

5 #12 Precise Process Description 1. Verify that emergency eyewash/shower is accessible and tested within last month. 2. Check the location and expiration of the Calcium Gluconate and that a copy of the MSDS for HF is available 3. During the entire process, carefully survey benchtop and floor area for any drips. Clean up spills immediately. 4. Ensure that the 55gl drum is placed correctly onto the secondary containment and that there is enough space left in the drum. 5. It is essential that you wear a face shield over your safety glasses, double neoprene gloves, and the neoprene aprons to ensure proper protection for concentrated acid spills. 6. While digestion the samples, no other work is allowed in the fume hood! 7. Take Teflon beaker of appropriate size for your sample (100, 250, 400, or 1000mL). Ensure that the Teflon beaker is labeled appropriately. Weigh sample precisely on the Fisher 225D scale. Pour in Teflon beaker and wetten thoroughly with milliq water. Use the same amount of milliq as your sample mass. For example, if you have a 25g sample, add ~12mL milliq. This step prevents the sample from splashing when the Hydrofluoric Acid is added. 8. Move Teflon beaker with sample to the FUME HOOD. All of the following steps are conducted in the FUME HOOD. 9. Work with one Teflon beaker (sample) at a time. Add the same amount of 49% Hydrofluoric Acid (HF) as your sample mass. Add 69% Nitric Acid (HNO3), use half of your sample amount. For example, if you have a 25g sample, add 25mL HF and 12mL HNO3. Work carefully and pour HF slowly. Wetten your sample in the first steps prevents 5

6 splashing and a strong exothermic reaction. Now, the acid mixture has a concentration of ~20% HF and ~30% HNO Place Teflon lid on the Teflon beaker and let sit for 1 hour. 11. The next steps involve heating the Teflon beaker on a hot plate. Ensure that all flammable and combustible materials are not kept near the hot plate. 12. Move Teflon beaker without lid to hot plate and heat to 65 C. This corresponds to setting 150 on the hot plates used in Mitchell A20. Evaporate to dryness. This may take up to 6 hours, depending on sample mass and volume of acid mixture used. While heating, lower the hood sash down as feasible. Note: This setting prevents the sample from boiling. Under no circumstances, you want to boil your sample. 13. Remove from hot plate and allow cooling for one hour. 14. Wetten your sample with a few ml milliq water. Add 2x the sample mass HF to your Teflon beaker. For example, for a 25g sample, add 50mL HF. 15. Place Teflon beaker on the hot plate and increase temperature setting to 200. This corresponds to a temperature of ~75 C. Observe closely for the next 2 hours. If sample is thoroughly heated and no foaming occurs, put lid on the Teflon beaker and heat for 24hrs. 16. Remove lid and evaporate to dryness. While heating and evaporating, lower the hood sash down as feasible. 17. If quartz is not completely dissolved, repeat HF dissolution from step The sample is now digested and the residue can be dissolved for further chemical processing. 6

Laboratory Spill Response Procedures Health Threatening Situation - In the event of an imminent or actual health-threatening emergency (threatening local or public health, safety, or welfare; or the

7 Laboratory Spill Response Procedures Health Threatening Situation - In the event of an imminent or actual health-threatening emergency (threatening local or public health, safety, or welfare; or the environment outside the immediate area): 1) CALL FOR THE FIRE DEPARTMENT REMAIN IN THE AREA TO ADVISE RESPONDERS. 2) ACTIVATE LOCAL ALARM SYSTEMS 3) Once personal safety is established, call EH&S at and proceed with local notifications, below. Non-Health Threatening Situation In the event of a spill or release which may or has impacted the environment (storm drain, soil, air outside the building) or spill or release that cannot be cleaned up by local personnel: 1) Notify Stanford Responders: call (24 hours/day, 7 days/week), then 2) Provide local notifications: Name Phone Number Cell or Pager Title George E. Hilley Principal Investigator Bodo Bookhagen (415) Lab Manager Felicia Morales Lab Safety Coordinator Local Response Situation In the event of a minor spill or release that can be cleaned up by local personnel using readily available equipment (absorbent, available from EH&S in Small Spill Kit): 1) Notify personnel in the area and restrict access. Eliminate all sources of ignition. 2) Wear gloves and protective eyewear. Clean up using absorbent. Put the contaminated absorbent in a labeled hazardous waste container. 3) If greater than 30 ml, or cleanup takes longer than 15 minutes, make a record in your lab inspection report, or call EH&S at to record the spill, and notify your supervisor. 4) Submit online waste pickup request to EH&S at: wastepickup.stanford.edu 7

Introduction to the General Chemistry II Laboratory. Lab Apparatus and Glassware

Introduction to the General Chemistry II Laboratory Lab Apparatus and Glassware Review the first of two photographs at the end of the Data Documentation section, near the beginning of your lab manual.